Technical Field
This present invention provides a system and method for protecting audio speakers, and more specifically, one that prevents the speakers from getting damaged regardless of audio content and user settings.
Background
The dynamic range of audio content intended to be used with a surround sound system can lead to damage to speakers when played at high volumes. In addition, the typical surround sound system is constructed with an audio amplifier that provides the same available power to all speakers while most systems have a mixture of large and small speakers.
A common configuration for actual surround sound installation may involve, for example, a pair of large floor standing front speakers, one located to the left and right of a display, a smaller center channel speaker located above the display, one located below or behind the display screen, and a number of small satellite speakers for surround and back channels.
Typically, the power handling capability of any large front speaker is usually significantly higher than the power handling capability of any center channel and surround channel. However, it is typical for amplifiers used for this application provide identical power to all of these speakers. As a result, this can lead to over driving the smaller speakers, for example, during playback intense audio action sequences. Moreover, most speakers are rated for short term power usage and cannot sustain operation continuously at this power rating. Likewise, if an end user operates a system at excessive volume settings, speaker coils may become damaged, for example, through overheating.
A typical home theater uses an A/V receiver is a device that provides an input selector switch, a surround sound decoder, a volume control function, and a power amplifier to drive speakers. With the latest high definition audio formats provided by BlueRay players, a powerful Digital Signal Processor (DSP) is necessary to decode and process surround sound content. Normally, additional signal processing is required to perform post processing such as bass management, dynamic range processing, and equalization.
Typically, dynamic range processing is usually limited to providing a “midnight mode” to reduce the dynamic range of the signals so that any on-screen transients (like gun shots and explosions) don't wake up the neighbors. However, this type of processing is not intended to protect the speakers and can even increase the likelihood of thermal damage. Since the peak power gets limited in midnight mode, the end user does not hear the undesirable sounds like clipping and short term speaker overload that would normally trigger the user to turn the volume down. Instead the speaker continues to heat up until the point of failure.
There is a desire to prevent damage to audio speakers. Accordingly, there is a need for an improved speaker protection for surround sound systems, devices and methods.